Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ascites fluid or peritoneal washings of DBA/2 mice bearing the P815 mastocytoma have been found to contain a chemotactic factor inactivator (CFI) which inactivates the bacterial chemotactic factor as well as the chemotactic activity associated with the C3 and C5 fragments when assayed on rabbit neutrophils. The amount of CFI is proportional to the number of tumor cells in the peritoneal exudate. The inactivator is also found in tumor cell hemogenates as well as in culture fluid from tumor cells growing in vitro. The activity is heat-labile but is not affected by protease inhibitors. Its molecular weight is greater than 50,000 daltons, based on Sephadex chromatography and sucrose density gradient ultracentrifugation studies. In C57BL/6 mice, which reject the mastocytoma, CFI levels decrease in proportion to the decreasing numbers of tumor cells.
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PMID:In vitro and in vivo production of chemotactic inhibitors by tumor cells. 10 32

Antigen-specific suppressor cells and suppressive extracts obtained from the thymuses of DBA/2 mice bearing small syngeneic P815 mastocytomas were compared for their immunogenetic properties and requirements. The assay for specific suppression involved the ability of either cells or extracts to inhibit the primary in vitro cytotoxic response of normal DBA/2 splenocytes to mitomycin-treated P815 cells. It was shown that pretreatment of suooressor cell populations with anti-Iad antiserum plus rabbit complement removed the suppressive activity. Similarly, absorption of the suppressor factor with anti-Iad antiserum removed the suppressive properties of the material. It was found that the suppressor cells, generated in DBA/2 tumor bearers, were capable of specifically suppressing the anti-P815 response of B6D2 F1 radiation chimeras possessing lymphoid cells of the H-2b or H-2t2 haplotype equally as well as they could suppress the response of H-2d-bearing effector cells. This indicates that the suppressor cells are not H-2 restricted with respect to K or D markers on the responder cells in this system.
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PMID:Further characterization of thymic suppressor cells and a factor that suppress the generation of cells cytotoxic for a syngeneic tumor in DBA/2 mice. 10 2

Growth of syngeneic P815 mastocytoma in DBA/2J male mice was evaluated as a result of various stress regimens. A single session of inescapable shock resulted in earlier tumor appearance, exaggeration of tumor size, and decreased survival time in recipient animals. Escapable shock had no such effects. The effects of the inescapable shock were mitigated if mice received long-term shock treatment.
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PMID:Stress and coping factors influence tumor growth. 10 24

Although not obviously immunogenic when developing intraperitoneally or subcutaneously, the P-815 mastocytoma cell induces a significant immune response when injected intradermally into the syngeneic host. In some animals the immune reaction leads to spontaneous tumor regression and survival of the animals, but in most cases the effectively initiated immune-reaction is abrogated by as yet unknown mechanisms. The T cell is identified as the killer cell both in vivo and in vitro during the described period of immune reactivity. By means of two antibodies from two different species, rendered specific for the P-815 tumor cell by in vivo absorption in DBA/2 mice, two distinct antigens have been identified, isolated and partially purified from P-815 cell membranes. One of them is obviously different from H-2 antigens, the other one shows striking similarities with H-2 antigens (molecular weight, lectin binding properties), but does not coprecipitate with H-2 antigens in an indirect precipitation assay, using Staph. aureus Cowan I as the Fc-binding agent.
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PMID:The stimulation of a T cell response in the syngeneic host by the P-815 mastocytoma cell and the isolation of a tumor-associated antigen which has some H-2 antigen characteristics. 11 88

Post-capillary venules (PVC) of the lymph nodes and Peyer's patches were studied in frozen sections stained with an indirect immunoperoxidase technique to demonstrate their endothelium-associated IgG in DBA/2 mice bearing mastocytoma. The previously established three types of IgG-distribution (luminal, intraendothelial and basement membrane site), each confined to one of the three PCV grades (graded on the basis of the endothelial cell height), were found in these tumor-bearing mice, too. This finding shows that the tool applied in T-lymphocyte deprivation, be it a tumor or anti-theta-globulin, does not influence the behavior of this IgG-distribution profile. This fact lends further support to the thesis that the endothelium-associated IgG could be involved in the regulation of the T-cell passage through the wall of the post-capillary venules.
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PMID:Endothelium-associated IgG in the post-capillary venules of the lymphatic tissues in mice bearing experimental neoplasia. 11 44

Peritoneal macrophages from non-immunised C57/bl, C3H, and DBA/2 mice were examined for their capability of inhibiting the growth of mastocytoma P-815 cells in vitro. The rate of tumour cell growth was measured by the uptake of 125IUDR into the DNA of the tumor cells. Sodium thioglycollate-induced macrophages as well as resident macrophages inhibited the growth of allogeneic tumor cells distinctly, when incubated for 48 h. The effect depended on the effector to target cell ratio. Tumor cell growth was still reduced at a ratio of one macrophage to one tumor cell. A decrease in the proliferative activity of mastocytoma cells was observed in the presence of non-stimulated and non-immune macrophages from DBA/2 mice. This decrease in target cell proliferation, however, occurred more slowly.
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PMID:Cytostatic effect of macrophages from non-immunised mice on mastocytoma P-815 cells in vitro. 11 16

The involvement of peritoneal macrophages in rejection of mastocytoma cells in the C57BL/6 mice was examined in comparison to similar cell responses in susceptible DBA/2 mice. By means of scanning and transmission electron microscopy it was found that macrophages constituted the major cell class responding to the mastocytoma cells in the peritoneum of both mouse strains. However, in the resistant mouse strain macrophages formed the predominant cell type during the course of tumor growth. Furthermore, tissue culture of peritoneal exudate cells from this resistant mouse strain injected with mastocytoma cells five days earlier failed to grow out tumor cells. On the other hand, macrophages decreased in number in the susceptible DBA/2 mouse strain and tumor cells did grow readily in vitro when peritoneal cells containing tumor cells and macrophages were cultured in vitro. These results indicate that macrophages constitute an important cell class in resistance of a mouse strain which is now susceptible to mastocytoma cells. The ultrastructural study provided some insight into the nature of the cell types involved and their interaction with the tumor cell.
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PMID:Involvement of peritoneal macrophages in cellular responses to mastocytoma in resistant and susceptible mice. 12 Oct 34

The mitogens concanavalin A (Con A) and bacterial lipopolysaccharide (LPS) stimulated normal spleen cells of DBA/2J, CBA/J, and BALB/c mice about equally in the presence of either isologous or homologous serum. This system revealed that sera from mice with five different methylcholanthrene-induced rhabdomyosarcomas inhibited mitogen stimulation of normal spleen cells. Sera from mice with a mammaryadenocarcinoma and spontaneous rhabdomyosarcoma were similarly suppressive. In contrast, sera from mice with melanoma were not inhibitory and often enhanced stimulation. Sera from tumor-bearing animals had the same effects both qualitatively and quantitatively on cells from the strain carrying the tumor and on cells from the other two strains. The mixed lymphocyte response of CBA/J times BALB/c spleen cells was affected exactly as were the responses to mitogen by the various sera. Stimulation by mitogen of mouse lymph-node cells and spleen cells with macrophages removed, as well as that of guinea pig spleen cells, was also inhibited by sera from mice with rhabdomyosarcoma and mammary adenocarcinoma.
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PMID:Effects of sera from tumor-bearing mice on mitogen and allogeneic cell stimulation of normal lymphoid cells. 12 99

1-(2-Chloroethyl)-3-(beta-D-glucopyranosyl)-1-nitrosourea (GANU), a water-soluble nitrosourea, differs from 2-[3-(2-chloroethyl)-3-nitrosoureido]-D-glucopyranose (chlorozotocin) by the placement of the cytotoxic group on C-1 of glucose. Its biological and biochemical properties are compared with those of chlorozotocin. At a 10% lethal dose (10 mg/kg i.p.), GANU demonstrates minimal myelosuppression. This dose failed to depress normal bone marrow DNA synthesis, in contrast to a 96% inhibition in L1210 DNA synthesis. In L1210 cell suspension, equimolar doses of GANU and chlorozotocin produced equivalent degrees of inhibition in DNA synthesis. GANU has significant L1210 activity in BALB/c X DBA/2 F1 mice treated on Day 2 of tumor growth. A 117% increased life-span and 15% 45-day survivors are atained with 15 mg/kg i.p., a 50% lethal dose. However, in concurrent studies using randomly selected littermate groups of mice, GANU proved less active than chlorozotocin which produced a 306% increased life-span (15 mg/kg i.p.). GANU and chlorozotocin have similar in vitro alkylating activity but the in vitro carbamoylating activity of GANU is sevenfold that of chlorozotocin. On a molar basis, the lethal toxicity of GANU is twice that of chlorozotocin. The significant carbamoylating activity of GANU may contribute to its greater toxicity and therefore limit the mumoles of alkylating agent that can be administered to the tumor. These structure-activity studies further confirm that the addition of a glucose carrier to a cytotoxic nitrosourea moiety can selectively reduce bone marrow toxicity while retaining antitumor activity.
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PMID:Biological and biochemical properties of 1-(2-chloroethyl)-3-(beta-D-glucopyranosyl)-1-nitrosourea (NSC D 254157), a nitrosourea with reduced bone marrow toxicity. 13 78

Spleen cells from mice with syngeneic tumor transplants are hyporesponsive in mixed-lymphocyte culture. The hyporesponsiveness is due to the activation of suppressor cells. Spleen from tumor-bearing mice, treated with mitomycin and added to normal mixed lymphocyte culture (with responding cells syngeneic to the added cells), inhibits proliferation of the responding cells. Suppressor activity in the spleen cells can be detected as early as 5 days after s.c. transplantation of P-815 mastocytoma into DBA/2 mice. Tumor cells placed in cell-impermeable i.p. diffusion chambers can also activate splenic suppressor cells. Suppressor cells can be activated in syngeneic mice by (DBA/2) P-815 cells, by (C3H) L25-cells, or by recent (C57BL/6) methylcholanthrene-induced tumors. The latter tumors retain their ability to activate suppressor cells after passaging in syngeneic mice. Only one tumor, induced with methylcholanthrene in DBA/2 mice, failed to activate suppressor cells. Suppressor activity in the spleen cells from mice with 20-day s.c. tumor transplants is not reduced after removal of glass-adherent cells. Suppressor activity is significantly decreased after removal of thymus-derived cells with anti-theta treatment and complement.
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PMID:Activation of suppressor cells by syngeneic tumor transplants in mice. 14 32


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